1. Field
Example embodiments relate to magnetic structures, methods of forming the same, and memory devices including a magnetic structure.
2. Description of the Related Art
Magnetic random access memories (MRAMs) are memory devices that store data by using a variation in resistance of a magnetic tunneling junction (MTJ) element of a memory cell. The resistance of the MTJ element varies according to a magnetization direction of a free layer. That is, when the magnetization direction of the free layer is the same as a magnetization direction of a pinned layer, the MTJ element has low resistance. When the magnetization direction of the free layer is opposite to the magnetization direction of the pinned layer, the MTJ element has high resistance. A case where the MTJ element has the low resistance may correspond to data ‘0’, and a case where the MTJ element has the high resistance may correspond to data ‘1’. Because such a MRAM is non-volatile is capable of high speed operations and has high endurance, the MRAM has gained attention as one of the next generation non-volatile memory devices.
In order to increase a recording density of MRAM (i.e., to obtain a high density MRAM), a size of the MTJ element has to be reduced. However, when the size of the MTJ element is reduced, thermal stability of data recorded in a data storage layer (i.e., free layer) decreases. Thus, securing a data retention characteristic becomes difficult. In this regard, it is not easy to increase the recording density of the MRAM over a certain level.